1 /*
2 * Copyright © 2016 Igalia S.L.
3 *
4 * This is part of HarfBuzz, a text shaping library.
5 *
6 * Permission is hereby granted, without written agreement and without
7 * license or royalty fees, to use, copy, modify, and distribute this
8 * software and its documentation for any purpose, provided that the
9 * above copyright notice and the following two paragraphs appear in
10 * all copies of this software.
11 *
12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
16 * DAMAGE.
17 *
18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
23 *
24 * Igalia Author(s): Frédéric Wang
25 */
26
27 #include "hb-open-type-private.hh"
28
29 #include "hb-ot-math-table.hh"
30
HB_SHAPER_DATA_ENSURE_DECLARE(ot,face) const31 HB_SHAPER_DATA_ENSURE_DECLARE(ot, face)
32
33 static inline const OT::MATH&
34 _get_math (hb_face_t *face)
35 {
36 if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return OT::Null(OT::MATH);
37 hb_ot_layout_t * layout = hb_ot_layout_from_face (face);
38 return *(layout->math.get ());
39 }
40
41 /*
42 * OT::MATH
43 */
44
45 /**
46 * hb_ot_math_has_data:
47 * @face: #hb_face_t to test
48 *
49 * This function allows to verify the presence of an OpenType MATH table on the
50 * face.
51 *
52 * Return value: true if face has a MATH table, false otherwise
53 *
54 * Since: 1.3.3
55 **/
56 hb_bool_t
hb_ot_math_has_data(hb_face_t * face)57 hb_ot_math_has_data (hb_face_t *face)
58 {
59 return &_get_math (face) != &OT::Null(OT::MATH);
60 }
61
62 /**
63 * hb_ot_math_get_constant:
64 * @font: #hb_font_t from which to retrieve the value
65 * @constant: #hb_ot_math_constant_t the constant to retrieve
66 *
67 * This function returns the requested math constants as a #hb_position_t.
68 * If the request constant is HB_OT_MATH_CONSTANT_SCRIPT_PERCENT_SCALE_DOWN,
69 * HB_OT_MATH_CONSTANT_SCRIPT_SCRIPT_PERCENT_SCALE_DOWN or
70 * HB_OT_MATH_CONSTANT_SCRIPT_PERCENT_SCALE_DOWN then the return value is
71 * actually an integer between 0 and 100 representing that percentage.
72 *
73 * Return value: the requested constant or 0
74 *
75 * Since: 1.3.3
76 **/
77 hb_position_t
hb_ot_math_get_constant(hb_font_t * font,hb_ot_math_constant_t constant)78 hb_ot_math_get_constant (hb_font_t *font,
79 hb_ot_math_constant_t constant)
80 {
81 const OT::MATH &math = _get_math (font->face);
82 return math.get_constant(constant, font);
83 }
84
85 /**
86 * hb_ot_math_get_glyph_italics_correction:
87 * @font: #hb_font_t from which to retrieve the value
88 * @glyph: glyph index from which to retrieve the value
89 *
90 * Return value: the italics correction of the glyph or 0
91 *
92 * Since: 1.3.3
93 **/
94 hb_position_t
hb_ot_math_get_glyph_italics_correction(hb_font_t * font,hb_codepoint_t glyph)95 hb_ot_math_get_glyph_italics_correction (hb_font_t *font,
96 hb_codepoint_t glyph)
97 {
98 const OT::MATH &math = _get_math (font->face);
99 return math.get_math_glyph_info().get_italics_correction (glyph, font);
100 }
101
102 /**
103 * hb_ot_math_get_glyph_top_accent_attachment:
104 * @font: #hb_font_t from which to retrieve the value
105 * @glyph: glyph index from which to retrieve the value
106 *
107 * Return value: the top accent attachment of the glyph or 0
108 *
109 * Since: 1.3.3
110 **/
111 hb_position_t
hb_ot_math_get_glyph_top_accent_attachment(hb_font_t * font,hb_codepoint_t glyph)112 hb_ot_math_get_glyph_top_accent_attachment (hb_font_t *font,
113 hb_codepoint_t glyph)
114 {
115 const OT::MATH &math = _get_math (font->face);
116 return math.get_math_glyph_info().get_top_accent_attachment (glyph, font);
117 }
118
119 /**
120 * hb_ot_math_is_glyph_extended_shape:
121 * @face: a #hb_face_t to test
122 * @glyph: a glyph index to test
123 *
124 * Return value: true if the glyph is an extended shape, false otherwise
125 *
126 * Since: 1.3.3
127 **/
128 hb_bool_t
hb_ot_math_is_glyph_extended_shape(hb_face_t * face,hb_codepoint_t glyph)129 hb_ot_math_is_glyph_extended_shape (hb_face_t *face,
130 hb_codepoint_t glyph)
131 {
132 const OT::MATH &math = _get_math (face);
133 return math.get_math_glyph_info().is_extended_shape (glyph);
134 }
135
136 /**
137 * hb_ot_math_get_glyph_kerning:
138 * @font: #hb_font_t from which to retrieve the value
139 * @glyph: glyph index from which to retrieve the value
140 * @kern: the #hb_ot_math_kern_t from which to retrieve the value
141 * @correction_height: the correction height to use to determine the kerning.
142 *
143 * This function tries to retrieve the MathKern table for the specified font,
144 * glyph and #hb_ot_math_kern_t. Then it browses the list of heights from the
145 * MathKern table to find one value that is greater or equal to specified
146 * correction_height. If one is found the corresponding value from the list of
147 * kerns is returned and otherwise the last kern value is returned.
148 *
149 * Return value: requested kerning or 0
150 *
151 * Since: 1.3.3
152 **/
153 hb_position_t
hb_ot_math_get_glyph_kerning(hb_font_t * font,hb_codepoint_t glyph,hb_ot_math_kern_t kern,hb_position_t correction_height)154 hb_ot_math_get_glyph_kerning (hb_font_t *font,
155 hb_codepoint_t glyph,
156 hb_ot_math_kern_t kern,
157 hb_position_t correction_height)
158 {
159 const OT::MATH &math = _get_math (font->face);
160 return math.get_math_glyph_info().get_kerning (glyph, kern, correction_height, font);
161 }
162
163 /**
164 * hb_ot_math_get_glyph_variants:
165 * @font: #hb_font_t from which to retrieve the values
166 * @glyph: index of the glyph to stretch
167 * @direction: direction of the stretching
168 * @start_offset: offset of the first variant to retrieve
169 * @variants_count: maximum number of variants to retrieve after start_offset
170 * (IN) and actual number of variants retrieved (OUT)
171 * @variants: array of size at least @variants_count to store the result
172 *
173 * This function tries to retrieve the MathGlyphConstruction for the specified
174 * font, glyph and direction. Note that only the value of
175 * #HB_DIRECTION_IS_HORIZONTAL is considered. It provides the corresponding list
176 * of size variants as an array of hb_ot_math_glyph_variant_t structs.
177 *
178 * Return value: the total number of size variants available or 0
179 *
180 * Since: 1.3.3
181 **/
182 unsigned int
hb_ot_math_get_glyph_variants(hb_font_t * font,hb_codepoint_t glyph,hb_direction_t direction,unsigned int start_offset,unsigned int * variants_count,hb_ot_math_glyph_variant_t * variants)183 hb_ot_math_get_glyph_variants (hb_font_t *font,
184 hb_codepoint_t glyph,
185 hb_direction_t direction,
186 unsigned int start_offset,
187 unsigned int *variants_count, /* IN/OUT */
188 hb_ot_math_glyph_variant_t *variants /* OUT */)
189 {
190 const OT::MATH &math = _get_math (font->face);
191 return math.get_math_variants().get_glyph_variants (glyph, direction, font,
192 start_offset,
193 variants_count,
194 variants);
195 }
196
197 /**
198 * hb_ot_math_get_min_connector_overlap:
199 * @font: #hb_font_t from which to retrieve the value
200 * @direction: direction of the stretching
201 *
202 * This function tries to retrieve the MathVariants table for the specified
203 * font and returns the minimum overlap of connecting glyphs to draw a glyph
204 * assembly in the specified direction. Note that only the value of
205 * #HB_DIRECTION_IS_HORIZONTAL is considered.
206 *
207 * Return value: requested min connector overlap or 0
208 *
209 * Since: 1.3.3
210 **/
211 hb_position_t
hb_ot_math_get_min_connector_overlap(hb_font_t * font,hb_direction_t direction)212 hb_ot_math_get_min_connector_overlap (hb_font_t *font,
213 hb_direction_t direction)
214 {
215 const OT::MATH &math = _get_math (font->face);
216 return math.get_math_variants().get_min_connector_overlap (direction, font);
217 }
218
219 /**
220 * hb_ot_math_get_glyph_assembly:
221 * @font: #hb_font_t from which to retrieve the values
222 * @glyph: index of the glyph to stretch
223 * @direction: direction of the stretching
224 * @start_offset: offset of the first glyph part to retrieve
225 * @parts_count: maximum number of glyph parts to retrieve after start_offset
226 * (IN) and actual number of parts retrieved (OUT)
227 * @parts: array of size at least @parts_count to store the result
228 * @italics_correction: italic correction of the glyph assembly
229 *
230 * This function tries to retrieve the GlyphAssembly for the specified font,
231 * glyph and direction. Note that only the value of #HB_DIRECTION_IS_HORIZONTAL
232 * is considered. It provides the information necessary to draw the glyph
233 * assembly as an array of #hb_ot_math_glyph_part_t.
234 *
235 * Return value: the total number of parts in the glyph assembly
236 *
237 * Since: 1.3.3
238 **/
239 unsigned int
hb_ot_math_get_glyph_assembly(hb_font_t * font,hb_codepoint_t glyph,hb_direction_t direction,unsigned int start_offset,unsigned int * parts_count,hb_ot_math_glyph_part_t * parts,hb_position_t * italics_correction)240 hb_ot_math_get_glyph_assembly (hb_font_t *font,
241 hb_codepoint_t glyph,
242 hb_direction_t direction,
243 unsigned int start_offset,
244 unsigned int *parts_count, /* IN/OUT */
245 hb_ot_math_glyph_part_t *parts, /* OUT */
246 hb_position_t *italics_correction /* OUT */)
247 {
248 const OT::MATH &math = _get_math (font->face);
249 return math.get_math_variants().get_glyph_parts (glyph, direction, font,
250 start_offset,
251 parts_count,
252 parts,
253 italics_correction);
254 }
255